MacNeill's defense lawyers said heart problems were a contributing factor in the death of Michele MacNeill, and that the once-prominent doctor isn't a murderer.

Earlier today, Vanessa MacNeill, one of MacNeill's daughters, testified that she participated on a family panel to hire a new nanny days after her mother died. The only candidate her father presented, she said, was Willis.

Sabrina MacNeill, 19, said Willis moved in shortly after her mother's death, however she never recalled Willis doing any typical nanny duties.

"She didn't do much. She made spaghetti once and that was the only time she ever cooked," Sabrina MacNeill said.

Even though Willis had a room downstairs at the family's home, Sabrina MacNeill said she noticed the nanny would go upstairs to her father's room at night and that the door would then be closed.

"I remember staying up at night and [thinking], 'What in the world? I thought she was our nanny. Why is she up in dad's room?'" she said.

Willis testified on Tuesday that she had been carrying on an affair with the married doctor, and that their relationship remained sexual, even after he hired her to be a live-in nanny to his children.

The relationship between MacNeill and Willis moved full-speed ahead, and by late June, the couple were looking for wedding rings online, prosecutors noted. During a trip to Wyoming in July, just months after his wife died, MacNeill proposed to Willis at a restaurant with a four-and-a-half carat diamond ring.

Willis' mother, who testified Tuesday, said the family was "giddy" to have MacNeill, who is both a doctor and lawyer, in the family.

"Martin MacNeill is a very impressive person. He's tall, he has a bright white smile. He holds the title of doctor and also attorney," Vicki Willis said. "We were pleased, of course. Who wouldn't be?"